Oxidation during washing of fish meat induces a decrease in gel forming ability

Abstract

In order to examine the effect of oxidation during washing on the gel forming ability, fish meats were washed with CuCh solution and heated in the presence of ethylenediamine tetraacetic acid (EDTA) to prevent further oxidation. By washing with CuCh solution, myosin heavy chain (MHC) dimer was formed in the washed meat by disulfide bonds through oxidation of SH groups. The gel strength of gels from oxidized meats was lower than that of control meat. In the gels, polymerization of MHC and actin by disulfide bonds was observed in spite of little oxidation. The oxidized meat paste was mixed with NEM (SH blocking agent) and was heated to prepare gel to examine the effect of inhibiting the polymerization. The resulting gel was still weaker in gel strength than that of the control gel. Moreover, the effect of oxidation during washing was compared with that of oxidation after salt grinding. The gel from oxidized meat after grinding showed almost no decrease in gel strength, though the polymerization of MHC and actin through disulfide bonding occurred accompanying by the oxidation of SH groups. It was suggested that the dimer formation by oxidation during washing influenced to weaken the gel forming ability, being different from the contribution of oxidation in the meat paste after grinding with 3 % salt to gel forming ability. Therefore, meat washing should be careful not to oxidize the meat in order to produce a good quality surimi.